It is given that in a group of 3 students, the probability of 2 students not having the same birthday is 0.992. What is the probability that the 2 students have the same birthday?
The probability that the 2 students have the same birthday is 0.008.
The two events “having the same birthday” and “not having the same birthday” are complementary, so their probabilities add to 1. Hence P(same birthday) = 1 − 0.992 = 0.008.